1. Field of the Invention
The present invention relates to fire extinguishers and compositions suitable for use in fire extinguishers, particular suspensions including a fire extinguishing material and a carrier disseminated in a high volume and uniform suspension (which may or may not be an emulsion) of very fine droplets of a liquid agent, and a gaseous component, the gaseous component providing the propulsion for the suspension, wherein the gaseous component as a carrier in addition to the liquid agent as a fire extinguishing material are both effective in extinguishing fire.
2. Description of the Related Art
Fire extinguishing agents are stored in a single condensed phase, in a container, pressurized with their own vapor pressure and/or the pressure of an additional gas. Agents currently are chosen from the following set of materials: water with or without an antifreeze agent; CO.sub.2 ; various dry powders; and various halons and other halocarbons (including hydro-halocarbons). Agents may also be stored in an unpressurized condition, and pressurized when used, e.g., water-acid-soda extinguishers and gas-generating cartridges used to expel extinguishing agents upon demand. Misting agents such as water have been shown to be highly efficient in extinguishing fires; however, because of the high aerodynamic drag of small particles, there is an unsolved problem in making them fill an enclosure as well as a vaporizing material, such as Halon 1301 or CO.sub.2 fills an enclosure. At room temperature, the fire extinguishing agents, Halon 1301 and CO.sub.2 are stored as liquids in pressurized containers. The equilibrium vapor pressure of CO.sub.2 is about 700 psi, and that of Halon 1301 is about 200 psi. When the valve of either container is opened, gaseous material is expelled, and the remaining liquid quickly vaporizes and is discharged from the container. As the vapors enter the air, they tend to completely and quickly permeate the entire volume. Both of these materials are available from any fire extinguisher supply company, e.g., Kidde-Graviner. Dual-flow nozzles, used to shear relatively large liquid droplets into fine droplets, are an attempt to overcome the problems of producing a large volume of fine droplets, and propelling them through air. However, these nozzles, which require that one of the fluids be a gas to assist in formation of the small droplets, produce a directional flow of fine particles and do not solve the problem of filling a volume with small droplets of the agent.